2011/04/28 by W. K. Brooks, S. Strauch, K. Tsushima · 25 citations
Physics and Astronomy · #Hadron #High-Energy Particle Collisions Research #Meson #Nuclear physics #Nucleon #Particle physics #Particle physics theoretical and experimental studies #Parton #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Quark #hep-ex #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1088/1742-6596/299/1/012011
published in Journal of Physics Conference Series 299, 012011 (IOP Publishing) · to appear in J. Phys.: Conf. Proc. "New Insights into the Structure of Matter: The First Decade of Science at Jefferson Lab", eds. D. Higinbotham, W. Melnitchouk, A. Thomas; added references
arxiv created 2011/04/28 · openalex publication_date 2011/05/01 · arxiv updated 2011/06/15 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Chiral symmetry is one of the most fundamental symmetries in QCD. It is closely connected to hadron properties in the nuclear medium via the reduction of the quark condensate < q >, manifesting the partial restoration of chiral symmetry. To better understand this important issue, a number of Jefferson Lab experiments over the past decade have focused on understanding properties of mesons and nucleons in the nuclear medium, often benefiting from the high polarization and luminosity of the CEBAF accelerator. In particular, a novel, accurate, polarization transfer measurement technique revealed for the first time a strong indication that the bound proton electromagnetic form factors in 4 He may be modified compared to those in the vacuum. Second, the photoproduction of vector mesons on various nuclei has been measured via their decay to e + e − to study possible in-medium effects on the properties of the ρ meson. In this experiment, no significant mass shift and some broadening consistent with expected collisional broadening for the ρ meson has been observed, providing tight constraints on model calculations. Finally, processes involving in-medium parton propagation have been studied. The medium modifications of the quark fragmentation functions have been extracted with much higher statistical accuracy than previously possible.